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The Honorable Jason Keding -2 December 3, 2021 Supervisor of Town of Boston estimated cost of this alternative would range between $1,750,000 and $3,750,000 (Point Estimate $2,500,000). See Figure 1 for project limits. This secondary feed is supplied from the Wohlhueter Tank. As part of our evaluation of this alternative, the ECWA Engineering Department completed hydraulic modeling to verify and evaluate the impact of this secondary connection on the system. The results suggest that the Ward Pump Station and Wohlhueter Tank have sufficient capacity to supply this feed. Further, this connection would supply sufficient pressure equivalent to existing conditions, but available fire flow could be negatively impacted. In addition to providing a secondary supply to the area, based on the potential route of the new interconnecting main, there is a potential to provide public water service to approximately 17 residential properties currently supplied off private well systems. Alternative 2 – Wohlhueter Tank Service Area via Boston Cross Road Alternative 2 would require the installation of approximately 6,700 LF of 10” watermain from the existing dead end along Boston Cross Road (west of Powerline Road) to Cole Road, then north along Cole Road until the existing dead end near 8859 Cole Road. This alignment would require one trenchless road crossing, 3 PRV chambers, and 12 gate valves. The estimated cost of this project alternative would range between $1,470,000 and $3,150,000 (Point Estimate $2,100,000). See Figure 1 for project limits. Similar to Alternative 1, our overall evaluation suggests the Ward Pump Station and Wohlhueter Tank have sufficient capacity to supply this at sufficient pressure equivalent to existing conditions. However, available fire flow to that area could again be negatively impacted. Again, like Alternative 1, under this alternative there is a potential to provide public water service to approximately 13 residential properties currently supplied off private well systems. Alternative 3 – Rice Hill Tank Service Area via Polish Hill / Hillcroft Road The Polish Hill / Hillcroft Road Alternative 3 would require the installation of approximately 4,800 LF of 10” watermain from the existing main at Zimmerman Road along Polish Hill Road, then under Route 219 continuing along Hillcroft Road to the existing dead end near 6331 Hillcroft Road. This alignment would require one trenchless road crossing (800 LF HDD under RT 219), 2 PRV chambers, and 8 gate valves. The estimated cost of this alternative would range between $1,120,000 and $2,400,000 (Point Estimate $1,600,000). See Figure 1 for project limits. This connection would again supply sufficient pressure equivalent to existing conditions. However, unlike Alternatives 1 and 2, available fire flow in the area could be positively impacted. Note also that since this secondary feed is supplied from the Rice Hill Tank and the Keller Pump Station, the hydraulics of this system were evaluated. The results suggest that under a fire flow condition when the secondary source will be needed most, the normal station operation of a single pump will not be able to maintain minimum Rice Hill service area pressures as the tank levels drop rapidly. However, both the Keller Pump Station and Rice Hill Tank have sufficient capacity to supply this feed provided that two pumps are running concurrently the full duration of the